In order to fabricate a flexible display device, many display members made of organic materials have been developed, for example, an organic light emitting layer, an organic passivation layer, and a polymer substrate (e.g., a PI substrate) serving as a flexible substrate. However, it is infeasible to replace metallic wiring in a display with organic materials because the electrical conductivity of organic materials is much lower than that of the metallic wire. When a flexible display device is being bent, the metallic wiring in the display panel may break (the ratio is about 1%), resulting in failure of the display device.